The invention relates to a coaxial-type differential transmission apparatus, and in particular to a coaxial-type differential transmission apparatus providing reduction and acceleration output functions.
A gear reduction mechanism is commonly used in power transmission devices. A gear reduction mechanism can reduce rotational speed of a power source, such as a motor or an engine, and thereby increase torque output therefrom.
To obtain a high reduction ratio, a conventional gear reduction mechanism requires multiple corresponding gear sets integrated with complex components. Moreover, since the conventional gear reduction mechanism requires a complicated housing to accommodate the gear sets and complex components, the size or volume thereof is inevitably large. The total weight of the conventional gear reduction mechanism is thus increased, causing inconvenience when employed in mechanical devices requiring reduction output.
Additionally, the conventional gear reduction mechanism presents the following drawbacks. Manufacture, processing, and assembly of components can be complicated, and material for components is not easily obtained. Further, integration of multiple gear sets incurs loss of power transmission among gears, backlash between gears, and assembly or accumulated errors can directly affect operative precision of the conventional gear reduction mechanism.
Moreover, in the conventional gear reduction mechanism, a belt is connected to a flywheel (or a metal disk) to transmit power from the motor or engine to the periphery thereof, rotating the flywheel (metal disk). The conventional gear reduction mechanism can then perform power output by means of an output shaft. Accordingly, since an input shaft (rotating shaft of the motor or engine) is not coaxial to the output shaft, vibration can be easily generated in the conventional gear reduction mechanism, causing partial loss of power transmitted to the flywheel (metal disk) thereof.
Hence, there is a need to provide a highly efficient coaxial-type differential transmission apparatus providing a high reduction and acceleration ratio and reducing vibration and loss of power resulting therefrom.